CVE-2026-27645

MEDIUMPre-NVD 6.16.1—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.1 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4%, top 63% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Elevated
6.1EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.1Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

changedetection.io is a free open source web page change detection tool. In versions prior to 0.54.1, the RSS single-watch endpoint reflects the UUID path parameter directly in the HTTP response body without HTML escaping. Since Flask returns text/html by default for plain string responses, the browser parses and executes injected JavaScript. Version 0.54.1 contains a fix for the issue.

CVSS v3
6.1
EG Score
6.1(medium)
EG Risk
43(Track)
EG Risk 43/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity61% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
38%
KEV
Not listed

Published

February 25, 2026

Last Modified

June 17, 2026

Advisory Details (2)

Auto-updated Aug 4, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github.
github Patch Available🟡 PoC Available

Reflected XSS in RSS Single Watch Error Response <= (v0.53.6) · Advisory · dgtlmoon/changedetection.io · GitHub

https://github.com/dgtlmoon/changedetection.io/security/advisories/GHSA-mw8m-398g-h89w
github_commit Patch Available

commit a385c89abf44 (dgtlmoon/changedetection.io)

Patch available: dgtlmoon/changedetection.io 0.54.1 (contains commit a385c89abf44)

https://github.com/dgtlmoon/changedetection.io/commit/a385c89abf44b52fcfa20c7c6a6dd3047c4c1eb5

Affected Packages

(1 across 1 ecosystem)
PyPI(1)
PackageVulnerable rangeFixed inDependents
changedetection-io0.38.2 ... 0.53.7 (186 versions)0.54.1—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 7× in last 7d / 28× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-18 19:28 UTCEPSS rescore
  2. 2026-09-18 19:27 UTCEPSS rescore
  3. 2026-09-18 19:20 UTCOSV refresh
  4. 2026-09-17 19:30 UTCEPSS rescore
  5. 2026-09-16 14:08 UTCEPSS rescore
  6. 2026-09-16 05:15 UTCEPSS rescore
  7. 2026-09-13 16:47 UTCEPSS rescore
  8. 2026-09-12 15:01 UTCEPSS rescore
  9. 2026-09-11 14:52 UTCEPSS rescore
  10. 2026-09-10 09:34 UTCEPSS rescore
  11. 2026-09-08 22:00 UTCEPSS rescore
  12. 2026-09-07 16:01 UTCEPSS rescore
  13. 2026-09-06 13:47 UTCEPSS rescore
  14. 2026-09-06 13:47 UTCEPSS rescore
  15. 2026-09-04 05:06 UTCEPSS rescore
  16. 2026-09-02 14:11 UTCEPSS rescore
  17. 2026-09-01 13:53 UTCEPSS rescore
  18. 2026-09-01 04:39 UTCEPSS rescore
  19. 2026-08-30 22:47 UTCOSV refresh
  20. 2026-08-30 19:17 UTCEPSS rescore
  21. 2026-08-30 01:22 UTCEPSS rescore
  22. 2026-08-28 21:41 UTCEPSS rescore
  23. 2026-08-27 14:25 UTCEPSS rescore
  24. 2026-08-26 14:46 UTCEPSS rescore
  25. 2026-08-25 13:48 UTCEPSS rescore
Show 35 more
  1. 2026-08-23 00:19 UTCEPSS rescore
  2. 2026-08-21 23:49 UTCEPSS rescore
  3. 2026-08-20 22:55 UTCEPSS rescore
  4. 2026-08-19 17:03 UTCEPSS rescore
  5. 2026-08-18 13:48 UTCEPSS rescore
  6. 2026-08-17 13:47 UTCEPSS rescore
  7. 2026-08-16 14:56 UTCEPSS rescore
  8. 2026-08-16 02:14 UTCEPSS rescore
  9. 2026-08-15 01:30 UTCEPSS rescore
  10. 2026-08-14 09:04 UTCEG score recompute
  11. 2026-08-13 22:00 UTCEPSS rescore
  12. 2026-08-13 01:03 UTCEG score recompute
  13. 2026-08-12 13:50 UTCEPSS rescore
  14. 2026-08-11 13:42 UTCEPSS rescore
  15. 2026-08-11 08:43 UTCEG score recompute
  16. 2026-08-11 00:00 UTCEPSS rescore
  17. 2026-08-10 08:50 UTCEG score recompute
  18. 2026-08-09 13:46 UTCEPSS rescore
  19. 2026-08-09 08:41 UTCEG score recompute
  20. 2026-08-08 16:37 UTCEPSS rescore
  21. 2026-08-07 20:46 UTCEG score recompute
  22. 2026-08-06 13:46 UTCEPSS rescore
  23. 2026-08-06 03:03 UTCEG score recompute
  24. 2026-08-05 19:17 UTCEPSS rescore
  25. 2026-08-04 15:10 UTCEPSS rescore
  26. 2026-08-04 05:55 UTCEG score recompute
  27. 2026-08-03 10:36 UTCEPSS rescore
  28. 2026-08-02 19:36 UTCEG score recompute
  29. 2026-08-02 02:26 UTCEPSS rescore
  30. 2026-08-01 04:16 UTCEPSS rescore
  31. 2026-07-30 16:27 UTCEPSS rescore
  32. 2026-07-30 01:30 UTCEPSS rescore
  33. 2026-07-28 15:36 UTCEPSS rescore
  34. 2026-07-27 12:55 UTCEG score recompute
  35. 2026-07-27 12:50 UTCOSV refresh

Publicly available exploits

(1 reference)

Working exploit code is in the public domain. Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • Nucleihttp/cves/2026/CVE-2026-27645.yaml
    First seen Jan 1, 2026

    Changedetection.io RSS Single Watch - Cross-Site Scripting

    Open source ↗

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-27645?
CVE-2026-27645 is a medium vulnerability published on February 25, 2026. changedetection.io is a free open source web page change detection tool. In versions prior to 0.54.1, the RSS single-watch endpoint reflects the UUID path parameter directly in the HTTP response body without HTML escaping. Since Flask returns text/html by default for plain string responses, the…
When was CVE-2026-27645 disclosed?
CVE-2026-27645 was first published in the National Vulnerability Database on February 25, 2026, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-27645 actively exploited?
CVE-2026-27645 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 61.9% of all scored CVEs.
What is the CVSS score of CVE-2026-27645?
CVE-2026-27645 has a CVSS v3 base score of 6.1 (NVD).
How do I remediate CVE-2026-27645?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-27645, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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